Stephen J.LurieMD, PhD, Senior Editor
To the Editor: Dr Lacey and colleagues1 reported an increased risk of ovarian cancer in women who used unopposed estrogen, but not among women who used an estrogen-progestin combination. However, the histology of these tumors was described for only one third of the cases. A significant difference was found only for endometrioid cancers. Another study had similar findings, with only a significant increase in endometrioid and clear cell epithelial cancers among women receiving unopposed estrogen.2 In that study, the risk was greater in women who had received a tubal ligation or a hysterectomy, thus suggesting a possible role of estrogen-stimulating endometriosis.
Burry K, Cain JM. Estrogen Replacement Therapy and Risk of Ovarian Cancer in Postmenopausal Women. JAMA. 2002;288(20):2538. doi:10.1001/jama.288.20.2538